This revised Program Project proposal represents a continuation of a number of studies focussing on the role of psychosocial factors in the development of hypertension and cardiovascular disease. The proposed studies have several interrelated themes. One is to explore the relationships between environmental stress and blood pressure over a range of time courses, with acute laboratory studies at one extreme, and long- term prospective studies at the other. The basic model of stress includes three elements: the objective nature of the stressor, the individual's perception of it, and his or her physiological susceptibility. This model incorporates elements of the Karasek Job Strain model and the Frankenhaueser effort-distress model, with two components corresponding to demand and control. A third dimension will be social support. These models will be tested under both laboratory and field conditions. Blood pressure will be the main dependent variable, together with structural changes in the heart and carotid arteries. Five projects are included. Project l will evaluate the ability of ambulatory bloOd pressure, and blood pressure variability, to predict cardiovascular morbidity, and will also include a cross-sectional study comparing the relationships between blood pressure and target organ damage in black and white individuals. The hypothesis that white coat hypertension is a condition associated with lower risk than sustained hypertension will also be tested. Project 2 will prospectively evaluate the effects of job strain and social support on blood pressure and other outcome variables in a working population. Project 3 will study psychosocial and hormonal factors influencing diurnal variations of blood pressure in women, including the changes associated with menstruation and the menopause. Project 4 will assess within-subject changes of blood pressure in subjects exposed to changing levels of occupational stress over two months. Project 5 will examine the conceptual models of job strain, social support, and white coat hypertension in controlled laboratory conditions.